I found this definition on Medicine Net. You can click the link below to go to the website.
Liposarcoma: A malignant tumor that arises in fat cells in deep soft tissue, such as that inside the thigh. Most frequent in middle-aged and older adults (age 40 and above), liposarcomas are the most common of all soft-tissue sarcomas.
Note: My husband is not yet 38 yrs old.